From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28C3CC3A5A1 for ; Thu, 22 Aug 2019 17:28:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F14762064A for ; Thu, 22 Aug 2019 17:28:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494931; bh=MO3w8eOgsbjNExjFPHSc41pUyf7L1Ax8e6jm2SBydpg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=q648LkBMdTWNkDxpZ7e5WzIQMTUmK0aAYx1YUlAkxxMAkm5g4WyOQCOYoy71jAutN n3G6+2yHxaGHWxwU6ixTOQVrqGLegIfsFSAE/IZ5Qje0e7nizAtiaSiT37z44vE+SZ XQ2osGqlY8BKr7xD8TV3kqSsaI2dnbHBH+XiIKLw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391972AbfHVR1N (ORCPT ); Thu, 22 Aug 2019 13:27:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:50226 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389976AbfHVRZt (ORCPT ); Thu, 22 Aug 2019 13:25:49 -0400 Received: from localhost (wsip-184-188-36-2.sd.sd.cox.net [184.188.36.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7BFE023428; Thu, 22 Aug 2019 17:25:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494748; bh=MO3w8eOgsbjNExjFPHSc41pUyf7L1Ax8e6jm2SBydpg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KvPS86UFqC3d9mwIunY/tb2yVYWjgJa+W0oS6l+53NHdBQUkPErKqdiCx51gydr+W eGb8GENI7icvtpmXAIUtgUAw2kB+DCu//GUes3TUZrjH3yQBrXGZ4gNj5JWQieqHST 8lIniaQFu0cKxU28lOURGn20mX/U8idXW3n5125A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Fabrice Gasnier , Gottfried Haider , =?UTF-8?q?Michal=20Vok=C3=A1=C4=8D?= , Thierry Reding , John Keeping Subject: [PATCH 4.19 08/85] Revert "pwm: Set class for exported channels in sysfs" Date: Thu, 22 Aug 2019 10:18:41 -0700 Message-Id: <20190822171731.369519312@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190822171731.012687054@linuxfoundation.org> References: <20190822171731.012687054@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Fabrice Gasnier commit c289d6625237aa785b484b4e94c23b3b91ea7e60 upstream. This reverts commit 7e5d1fd75c3dde9fc10c4472b9368089d1b81d00 ("pwm: Set class for exported channels in sysfs") as it causes regression with multiple pwm chip[1], when exporting a pwm channel (echo X > export): - ABI (Documentation/ABI/testing/sysfs-class-pwm) states pwmX should be created in /sys/class/pwm/pwmchipN/pwmX - Reverted patch causes new entry to be also created directly in /sys/class/pwm/pwmX - 1st time, exporting pwmX will create an entry in /sys/class/pwm/pwmX - class attributes are added under pwmX folder, such as export, unexport npwm, symlinks. This is wrong as it belongs to pwmchipN. It may cause bad behavior and report wrong values. - when another export happens on another pwmchip, it can't be created (e.g. -EEXIST). This is causing the issue with multiple pwmchip. Example on stm32 (stm32429i-eval) platform: $ ls /sys/class/pwm pwmchip0 pwmchip4 $ cd /sys/class/pwm/pwmchip0/ $ echo 0 > export $ ls /sys/class/pwm pwm0 pwmchip0 pwmchip4 $ cd /sys/class/pwm/pwmchip4/ $ echo 0 > export sysfs: cannot create duplicate filename '/class/pwm/pwm0' ...Exception stack follows... This is also seen on other platform [2] [1] https://lkml.org/lkml/2018/9/25/713 [2] https://lkml.org/lkml/2018/9/25/447 Signed-off-by: Fabrice Gasnier Tested-by: Gottfried Haider Tested-by: Michal Vokáč Signed-off-by: Thierry Reding Cc: John Keeping Signed-off-by: Greg Kroah-Hartman --- drivers/pwm/sysfs.c | 1 - 1 file changed, 1 deletion(-) --- a/drivers/pwm/sysfs.c +++ b/drivers/pwm/sysfs.c @@ -263,7 +263,6 @@ static int pwm_export_child(struct devic export->pwm = pwm; mutex_init(&export->lock); - export->child.class = parent->class; export->child.release = pwm_export_release; export->child.parent = parent; export->child.devt = MKDEV(0, 0);